Insulated glazing

More energy-efficient and soundproof windows (glazing) can be achieved through multiple layers or through the use of coatings. Insulated glazing is an effective (but expensive) building element for these purposes.

Placement and size of the windows are also very important. Passive solar design considers the amount of sun that is captured, at what time of the year, and what time of the day, to warm when warmth is needed, and shield from heat during the hotter seasons and/or hotter parts of the day.

Multiple layer windows[edit | edit source]

Double-glazed windows[edit | edit source]

Double glazed windows are windows fitted with 2 panes of glass that have a space between them of approximately 12mm to 16mm. This space can be filled with air or with argon gas. The resulting effect is of insulated glazing which leads to reduced heat and noise transmission and, therefore, also to a warmer house.

Most double-glazed windows are made of PVC material. However, it is not uncommon for the frames to be also made of aluminium or wood.

Triple glazed windows[edit | edit source]

Triple glazed windows are similar to double-glazed ones. The main difference between them is that in triple glazing an extra panel is added. This extra panel adds a limited amount of extra insulation to the house which is a small improvement when compared to double glazed windows. Price-wise triple glazing costs substantially more than double glazing.

Advantages and disadvantages[edit | edit source]

The benefits are:

• Although the buying cost for insulated glazing is higher, the investment will be more than payed back as glazed windows can insulate your house up to 50-70% better.
• The double or triple glazed windows are stronger and, so, also safer.
• The better insulated windows can reduce with up to 60% the noise from the outside that gets into the house.
• Because double or triple glazed windows limit the amount of heat and sun transmittance from the outside, they can also lessen damage to your furniture, carpets, paintings and other objects.
• Insulated windows can increase the house value.
• Your carbon footprint can be reduced with insulated windows. This is because they can lessen significantly the greenhouse gas emissions (GHG) from heating and cooing.

The disadvantages are:

• Greater cost
• The windows must be kept closed to gain the full effect. The insulation effect is largely lost when the windows are opened. This may not be a big problem as:
  1. The windows may be opened at times of the day when the temperature is relatively comfortable.
  2. Ventilation may be achieved through a heat exchanger.^{[verification needed]} (How cost-effective is a heat exchanger as part of an energy-efficient house?^{[expansion needed]})

Use of inert gas such as argon adds to the efficiency, but at greater cost and it will leak out over perhaps 5 years. This is probably not cost-effective.^{[expansion needed]}

Cost effective design idea[edit | edit source]

This may be interresting for those on a tight budget that can't afford those new windows. Most of the windows in this house I have now are double glass already...but!...what the previous owner did was to put magentic strips around the edges of the window and add a removable panel of clear plexy glass. It is relativly thick plexy..not that thin flimzy stuff, the magnet strips create a very good seal, they can be removed to clean with a soft cloth and plexi is not that expensive. It is a great idea. I believe, it makes a significant difference to condensation, heat transfer, wind, noise and as a safety regarding protection if glass should get broken. - Yahoo! Answers - I want to get double pane, energy efficient windows for my home. How important is Argon gas a factor? (from a response posted by Jamie)

Alternatives[edit | edit source]

Thermal curtains. An advantage is that a tenant could invest in thermal curtains and take the curtains with them when they move.

The appropriate solution depends on the context. Especially with a new building, double glazing or other insulated glazing is a good choice.

External links[edit | edit source]

• Wikipedia:Insulated glazing
• GreenMatch - The Ultimate Guide to Double Glazed Windows. An in-depth article on double glazing which contains information on double glazed windows are, including costs, benefits, disadvantages and quotes for buying.
• GreenMatch - Why Double Glazing in the UK Is Here to Stay. Contains a comparison between double and triple glazed windows.